Cook pasta according to package directions; drain. In a large skillet, saute green pepper and onion in oil for 6-7 minutes. Add sausage; cook and stir until sausage is no longer pink. Drain. Stir in the spaghetti sauce and pasta.
Transfer to a 3-qt. baking dish coated with cooking spray. Cover and bake at 350° for 15-20 minutes. Uncover; sprinkle with cheeses. Bake 5-10 minutes longer or until cheese is melted.